Trade-in questions at a brand dealership?

I want to trade-in my 2006 Rabbit on a used Audi. I have a co-signer on the current loan I have for the Rabbit, but my new auto loan is just me. Does she have to go with me when I trade-in my vehicle? I am the first signer, she is the 2nd. Also, Is there anything special I need to do or take for a trade-in? Other than my car?